Syrian officials said last week that a tank filled with 15,000 tons of fuel had started leaking at a thermal power plant in the coastal city of Baniyas on August 23.
Authorities then said the leak was under control.
However, satellite images show that the emission is greater than first thought.
At present, it covers about 800 square kilometers, an area as large as the city of New York.
The concern for marine life is great.
According to a Baniyasbo, large parts of the coast have been polluted.
- The people did not need this.
It is already difficult to earn a living here and this has affected the lives of many families and caused them to lose their income.
"Takes necessary measures"
Turkey has also been affected by the leak.
"We are taking the necessary steps by mobilizing our resources to prevent the leak from becoming an environmental disaster," Vice President Fuat Oktay told Turkish state television.
In February, an oil spill polluted large parts of the eastern Mediterranean, along the coasts of Israel and Lebanon.